Matrix sensor for image touch sensing

ABSTRACT

Embodiments described herein include an input device, a display device having a capacitive sensing device, a processing system and a method for detecting presence of an input object using a capacitive sensing device. In one embodiment, an input device includes a plurality of sensor electrodes arranged in a planar matrix array. Each sensor electrode is coupled to unique routing trace and has an identical geometric plan form that is symmetrical about a center of area of the sensor electrode. The geometric plan form of each sensor electrode includes core and a plurality of protrusions extending outward from the core. The protrusions are configured to overlap with protrusions extending outward from each adjacent sensor electrode of the matrix array.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/042,661, filed on Sep. 30, 2013, which is incorporated by referencein its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

Embodiments of the present invention generally relate to a method andapparatus for touch sensing, and more specifically, a capacitive touchsensing device having grid electrodes for improved absolute sensing, andmethods for using the same.

Description of the Related Art

Input devices including proximity sensor devices (also commonly calledtouchpads or touch sensor devices) are widely used in a variety ofelectronic systems. A proximity sensor device typically includes asensing region, often demarked by a surface, in which the proximitysensor device determines the presence, location and/or motion of one ormore input objects. Proximity sensor devices may be used to provideinterfaces for the electronic system. For example, proximity sensordevices are often used as input devices for larger computing systems(such as opaque touchpads integrated in, or peripheral to, notebook ordesktop computers). Proximity sensor devices are also often used insmaller computing systems (such as touch screens integrated in cellularphones).

Many proximity sensor devices utilize an array of sensor electrodes tomeasure a change in capacitance indicative of the presence of an inputobject, such as a finger or stylus, proximate the sensor electrode. Somecapacitive implementations utilize “self capacitance” (or “absolutecapacitance”) sensing methods based on changes in the capacitivecoupling between sensor electrodes and an input object. In variousembodiments, an input object near the sensor electrodes alters theelectric field near the sensor electrodes, thus changing the measuredcapacitive coupling. In one implementation, an absolute capacitancesensing method operates by modulating sensor electrodes with respect toa reference voltage (e.g. system ground), and by detecting thecapacitive coupling between the sensor electrodes and input objects.Absolute capacitance sensing methods are very effective in detecting thepresence of a single input object, even when spaced far from the surfaceof the proximity sensor device.

Other capacitive implementations utilize “mutual capacitance” (or“transcapacitance”) sensing methods based on changes in the capacitivecoupling between sensor electrodes. In various embodiments, an inputobject near the sensor electrodes alters the electric field between thesensor electrodes, thus changing the measured capacitive coupling. Inone implementation, a transcapacitive sensing method operates bydetecting the capacitive coupling between one or more transmitter sensorelectrodes (also “transmitter electrodes”) and one or more receiversensor electrodes (also “receiver electrodes”). Transmitter sensorelectrodes may be modulated relative to a reference voltage (e.g.,system ground) to transmit transmitter signals. Receiver sensorelectrodes may be held substantially constant relative to the referencevoltage to facilitate receipt of a resulting signal. A resulting signalmay comprise effect(s) corresponding to one or more transmitter signals,and/or to one or more sources of environmental interference (e.g. otherelectromagnetic signals). Sensor electrodes may be dedicated transmitterelectrodes or receiver electrodes, or may be configured to both transmittransmitter signals and receive resulting signals. Transcapacitivesensing methods are very effective in detecting the presence of amultiple input objects in a sensing region and input objects that are inmotion. However, transcapacitive sensing methods generally rely oncompact electric fields which are not very effective for detecting thepresence or approach of objects spaced from the surface of the proximitysensor device.

Thus, there is a need for an improved proximity sensor device.

SUMMARY OF THE INVENTION

Embodiments described herein include a display device having acapacitive sensing device, a processing system and a method fordetecting presence of an input object using a capacitive sensing device,all of which include a grid electrode for improved absolute sensing.Other embodiments include a display device having a capacitive sensingdevice, a processing system and a method for detecting presence of aninput object using a capacitive sensing device, wherein the capacitivesensing device includes a matrix of discrete sensor electrodes.

In one embodiment, a display device having an integrated capacitivesensing device is provided. The display device includes a plurality ofsensor electrodes that each comprise at least one common electrodeconfigured to be driven for display updating and capacitive sensing. Agrid electrode is at least partially disposed between a first sensorelectrode and a second sensor electrode of the plurality of sensorelectrodes. The grid electrode is configured to shield the first sensorelectrode and the second sensor electrode. A processing system iscoupled to the sensor electrodes and the grid electrode. The processingsystem is configured to, in a first processing mode, modulate the firstsensor electrode and the second sensor electrode to acquire measurementsof changes in absolute capacitance indicative of positional informationfor an input object in a sensing region of the capacitive sensing devicebased on the measurements.

In another embodiment, a processing system for an input device isprovided. The processing system includes a sensor module having sensorcircuitry coupled to a grid electrode disposed between a first sensorelectrode and a second sensor electrode of a plurality of sensorelectrodes. Each of the plurality of sensor electrodes includes at leastone common electrode configured to be driven for display updating andcapacitive sensing. The sensor module is configured to, in a first modeof operation, modulate the first sensor electrode and the second sensorelectrode to acquire measurements of changes in absolute capacitancebetween the first sensor electrode, the second sensor electrode and aninput object and drive the grid electrode with a shielding signalconfigured to shield the first sensor electrode from the second sensorelectrode.

In yet another embodiment, a method for detecting presence of an inputobject using a capacitive sensing device is provided. The capacitivesensing device has a grid electrode disposed between a first sensorelectrode and a second sensor electrode of a plurality of sensorelectrodes, wherein each of the plurality of sensor electrodes includesat least one common electrodes of a display device. The method includesacquiring measurements of changes in absolute capacitive sensing bydriving onto and receiving with the first sensor electrode while in afirst mode of operation, driving the grid electrode with a shieldingsignal while in the first mode of operation, the shielding signal toshield the first sensor electrode and the second sensor electrode, anddetermining positional information based on the measurements of changesin absolute capacitive coupling.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 is a schematic block diagram of an input device.

FIG. 2A illustrates a simplified exemplary array of sensor elements thatmay be used in the input device of FIG. 1.

FIG. 2B illustrates an alternative array of sensor elements that may beused in the input device of FIG. 1.

FIG. 2C illustrates an alternative array of sensor elements that may beused in the input device of FIG. 1.

FIG. 2D illustrates yet another alternative array of sensor elementsthat may be used in the input device of FIG. 1.

FIG. 3 is a simplified sectional view of the sensor elements of FIG. 1illustrating the active portion of the sensor electrodes aligned withpixels elements of a display.

FIG. 4 is a simplified sectional view of another embodiment of thesensor assembly of FIG. 1 illustrating grid electrodes offset abovesensor electrodes.

FIG. 5 is a simplified sectional view of yet another embodiment of thesensor assembly of FIG. 1 illustrating grid electrodes offset abovesensor electrodes, wherein some sensor electrodes are aligned with thegrid electrodes.

FIG. 6 is a simplified schematic plan view of sensor elements operatingin a transcapacitive mode.

FIG. 7 is another simplified schematic plan view of sensor elementsoperating in a transcapacitive mode.

FIG. 8 is a flow diagram of one embodiment of a method for detectingpresence of an input object.

FIG. 9 is a flow diagram of another embodiment of a method for detectingpresence of an input object.

FIG. 10 is a flow diagram of yet another embodiment of a method fordetecting presence of an input object.

FIG. 11 is an exploded side view of one embodiment of an exemplarydisplay device having an integrated input device illustratingalternative locations for a grid electrode.

FIGS. 12A-12E illustrate various differently shaped sensor electrodesand grid electrodes.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized on other embodiments withoutspecific recitation. The drawings referred to here should not beunderstood as being drawn to scale unless specifically noted. Also, thedrawings are often simplified and details or components omitted forclarity of presentation and explanation. The drawings and discussionserve to explain principles discussed below, where like designationsdenote like elements.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and isnot intended to limit the invention or the application and uses of theinvention. Furthermore, there is no intention to be bound by anyexpressed or implied theory presented in the preceding technical field,background, brief summary or the following detailed description.

Various embodiments of the present technology provide input devices andmethods for improving usability. Particularly, embodiments describedherein advantageously utilized absolute sensing techniques to providegood input object location within a sensing region, even in applicationswhere multiple input objects are present or when the input object is inmotion. Additionally, some other embodiments provide for switchingbetween absolute and transcapacitive sensing mode, thus allowing theappropriate sensing mode to be utilized to best determine the positionand motion of one or more objects within the sensing region.

FIG. 1 is a schematic block diagram of an input device 100 in accordancewith embodiments of the present technology. In one embodiment, inputdevice 100 comprises a display device comprising an integrated sensingdevice. Although the illustrated embodiments of the present disclosureare shown integrated with a display device, it is contemplated that theinvention may be embodied in the input devices that are not integratedwith display devices. The input device 100 may be configured to provideinput to an electronic system 150. As used in this document, the term“electronic system” (or “electronic device”) broadly refers to anysystem capable of electronically processing information. Somenon-limiting examples of electronic systems include personal computersof all sizes and shapes, such as desktop computers, laptop computers,netbook computers, tablets, web browsers, e-book readers, and personaldigital assistants (PDAs). Additional example electronic systems includecomposite input devices, such as physical keyboards that include inputdevice 100 and separate joysticks or key switches. Further exampleelectronic systems include peripherals such as data input devices(including remote controls and mice), and data output devices (includingdisplay screens and printers). Other examples include remote terminals,kiosks, and video game machines (e.g., video game consoles, portablegaming devices, and the like). Other examples include communicationdevices (including cellular phones, such as smart phones), and mediadevices (including recorders, editors, and players such as televisions,set-top boxes, music players, digital photo frames, and digitalcameras). Additionally, the electronic system could be a host or a slaveto the input device.

The input device 100 can be implemented as a physical part of theelectronic system, or can be physically separate from the electronicsystem. As appropriate, the input device 100 may communicate with partsof the electronic system using any one or more of the following: buses,networks, and other wired or wireless interconnections. Examples includeI²C, SPI, PS/2, Universal Serial Bus (USB), Bluetooth, RF, and IRDA.

In FIG. 1, the input device 100 is shown as a proximity sensor device(also often referred to as a “touchpad” or a “touch sensor device”)configured to sense input provided by one or more input objects 140 in asensing region 170. Example input objects include fingers and styli, asshown in FIG. 1.

Sensing region 170 encompasses any space above, around, in and/or nearthe input device 100 in which the input device 100 is able to detectuser input (e.g., user input provided by one or more input objects 140).The sizes, shapes, and locations of particular sensing regions may varywidely from embodiment to embodiment. In some embodiments, the sensingregion 170 extends from a surface of the input device 100 in one or moredirections into space until signal-to-noise ratios prevent sufficientlyaccurate object detection. The distance to which this sensing region 170extends in a particular direction, in various embodiments, may be on theorder of less than a millimeter, millimeters, centimeters, or more, andmay vary significantly with the type of sensing technology used and theaccuracy desired. Thus, some embodiments sense input that comprises nocontact with any surfaces of the input device 100, contact with an inputsurface (e.g. a touch surface) of the input device 100, contact with aninput surface of the input device 100 coupled with some amount ofapplied force or pressure, and/or a combination thereof. In variousembodiments, input surfaces may be provided by surfaces of casingswithin which the sensor electrodes reside, by face sheets applied overthe sensor electrodes or any casings, etc. In some embodiments, thesensing region 170 has a rectangular shape when projected onto an inputsurface of the input device 100.

The input device 100 may utilize any combination of sensor componentsand sensing technologies to detect user input in the sensing region 170.The input device 100 comprises a plurality of sensing elements 124 fordetecting user input. The sensing elements 124 include a plurality ofsensor electrodes 120 and one or more grid electrodes 122. As severalnon-limiting examples, the input device 100 may use capacitive,elastive, resistive, inductive, magnetic acoustic, ultrasonic, and/oroptical techniques.

Some implementations are configured to provide images that span one,two, three, or higher dimensional spaces. Some implementations areconfigured to provide projections of input along particular axes orplanes.

In some resistive implementations of the input device 100, a flexibleand conductive first layer is separated by one or more spacer elementsfrom a conductive second layer. During operation, one or more voltagegradients are created across the layers. Pressing the flexible firstlayer may deflect it sufficiently to create electrical contact betweenthe layers, resulting in voltage outputs reflective of the point(s) ofcontact between the layers. These voltage outputs may be used todetermine positional information.

In some inductive implementations of the input device 100, one or moresensing elements 124 pickup loop currents induced by a resonating coilor pair of coils. Some combination of the magnitude, phase, andfrequency of the currents may then be used to determine positionalinformation.

In some capacitive implementations of the input device 100, voltage orcurrent is applied to create an electric field. Nearby input objectscause changes in the electric field, and produce detectable changes incapacitive coupling that may be detected as changes in voltage, current,or the like.

Some capacitive implementations utilize arrays or other regular orirregular patterns of capacitive sensing elements 124 to create electricfields. In some capacitive implementations, separate sensing elements124 may be ohmically shorted together to form larger sensor electrodes.Some capacitive implementations utilize resistive sheets, which may beuniformly resistive.

As discussed above, some capacitive implementations utilize “selfcapacitance” (or “absolute capacitance”) sensing methods based onchanges in the capacitive coupling between sensor electrodes 120 and aninput object. In various embodiments, an input object near the sensorelectrodes 120 alters the electric field near the sensor electrodes 120,thus changing the measured capacitive coupling. In one implementation,an absolute capacitance sensing method operates by modulating sensorelectrodes 120 with respect to a reference voltage (e.g. system ground),and by detecting the capacitive coupling between the sensor electrodes120 and input objects 140.

Additionally as discussed above, some capacitive implementations utilize“mutual capacitance” (or “transcapacitance”) sensing methods based onchanges in the capacitive coupling between sensor electrodes 120. Invarious embodiments, an input object 140 near the sensor electrodes 120alters the electric field between the sensor electrodes 120, thuschanging the measured capacitive coupling. In one implementation, atranscapacitive sensing method operates by detecting the capacitivecoupling between one or more transmitter sensor electrodes (also“transmitter electrodes”) and one or more receiver sensor electrodes(also “receiver electrodes”) as further described below. Transmittersensor electrodes may be modulated relative to a reference voltage(e.g., system ground) to transmit a transmitter signals. Receiver sensorelectrodes may be held substantially constant relative to the referencevoltage to facilitate receipt of resulting signals. A resulting signalmay comprise effect(s) corresponding to one or more transmitter signals,and/or to one or more sources of environmental interference (e.g. otherelectromagnetic signals). Sensor electrodes 120 may be dedicatedtransmitter electrodes or receiver electrodes, or may be configured toboth transmit and receive.

In FIG. 1, the processing system 110 is shown as part of the inputdevice 100. The processing system 110 is configured to operate thehardware of the input device 100 to detect input in the sensing region170. The processing system 110 comprises parts of or all of one or moreintegrated circuits (ICs) and/or other circuitry components. (Forexample, a processing system for a mutual capacitance sensor device maycomprise transmitter circuitry configured to transmit signals withtransmitter sensor electrodes, and/or receiver circuitry configured toreceive signals with receiver sensor electrodes). In some embodiments,the processing system 110 also comprises electronically-readableinstructions, such as firmware code, software code, and/or the like. Insome embodiments, components composing the processing system 110 arelocated together, such as near sensing element(s) 124 of the inputdevice 100. In other embodiments, components of processing system 110are physically separate with one or more components close to sensingelement(s) 124 of input device 100, and one or more componentselsewhere. For example, the input device 100 may be a peripheral coupledto a desktop computer, and the processing system 110 may comprisesoftware configured to run on a central processing unit of the desktopcomputer and one or more ICs (perhaps with associated firmware) separatefrom the central processing unit. As another example, the input device100 may be physically integrated in a phone, and the processing system110 may comprise circuits and firmware that are part of a main processorof the phone. In some embodiments, the processing system 110 isdedicated to implementing the input device 100. In other embodiments,the processing system 110 also performs other functions, such asoperating display screens, driving haptic actuators, etc.

The processing system 110 may be implemented as a set of modules thathandle different functions of the processing system 110. Each module maycomprise circuitry that is a part of the processing system 110,firmware, software, or a combination thereof. In various embodiments,different combinations of modules may be used. Example modules includehardware operation modules for operating hardware such as sensorelectrodes and display screens, data processing modules for processingdata such as sensor signals and positional information, and reportingmodules for reporting information. Further example modules includesensor operation modules configured to operate sensing element(s) 124 todetect input, identification modules configured to identify gesturessuch as mode changing gestures, and mode changing modules for changingoperation modes.

In some embodiments, the processing system 110 responds to user input(or lack of user input) in the sensing region 170 directly by causingone or more actions. Example actions include changing operation modes,as well as GUI actions such as cursor movement, selection, menunavigation, and other functions. In some embodiments, the processingsystem 110 provides information about the input (or lack of input) tosome part of the electronic system (e.g. to a central processing systemof the electronic system that is separate from the processing system110, if such a separate central processing system exists). In someembodiments, some part of the electronic system processes informationreceived from the processing system 110 to act on user input, such as tofacilitate a full range of actions, including mode changing actions andGUI actions.

For example, in some embodiments, the processing system 110 operates thesensing element(s) 124 of the input device 100 to produce electricalsignals indicative of input (or lack of input) in the sensing region170. The processing system 110 may perform any appropriate amount ofprocessing on the electrical signals in producing the informationprovided to the electronic system. For example, the processing system110 may digitize analog electrical signals obtained from the sensingelements 124. As another example, the processing system 110 may performfiltering, demodulation or other signal conditioning. In variousembodiments processing system 110 generates a capacitive image directlyfrom the resulting signals received with sensing elements 124 (sensorelectrodes 120). In other embodiments, processing system 110 spatiallyfilters (e.g., taking a difference, weighted sum of neighboringelements) the resulting signals received with sensing elements 124 (orsensor electrodes 120) to generate a sharpened or averaged image. As yetanother example, the processing system 110 may subtract or otherwiseaccount for a baseline, such that the information reflects a differencebetween the electrical signals and the baseline. As yet furtherexamples, the processing system 110 may determine positionalinformation, recognize inputs as commands, recognize handwriting, andthe like.

“Positional information” as used herein broadly encompasses absoluteposition, relative position, velocity, acceleration, and other types ofspatial information. Exemplary “zero-dimensional” positional informationincludes near/far or contact/no contact information. Exemplary“one-dimensional” positional information includes positions along anaxis. Exemplary “two-dimensional” positional information includesmotions in a plane. Exemplary “three-dimensional” positional informationincludes instantaneous or average velocities in space. Further examplesinclude other representations of spatial information. Historical dataregarding one or more types of positional information may also bedetermined and/or stored, including, for example, historical data thattracks position, motion, or instantaneous velocity over time.

In some embodiments, the input device 100 is implemented with additionalinput components that are operated by the processing system 110 or bysome other processing system. These additional input components mayprovide redundant functionality for input in the sensing region 170, orsome other functionality. FIG. 1 shows buttons 130 near the sensingregion 170 that can be used to facilitate selection of items using theinput device 100. Other types of additional input components includesliders, balls, wheels, switches, and the like. Conversely, in someembodiments, the input device 100 may be implemented with no other inputcomponents.

In some embodiments, the input device 100 comprises a touch screeninterface, and the sensing region 170 overlaps at least part of anactive area of a display screen of the display device 160. For example,the input device 100 may comprise substantially transparent sensingelements 124 overlaying the display screen and provide a touch screeninterface for the associated electronic system. The display screen maybe any type of dynamic display capable of displaying a visual interfaceto a user, and may include any type of light emitting diode (LED),organic LED (OLED), cathode ray tube (CRT), liquid crystal display(LCD), plasma, electroluminescence (EL), or other display technology.The input device 100 and the display device 160 may share physicalelements. For example, some embodiments may utilize some of the sameelectrical components for displaying and sensing (e.g., the activematrix control electrodes configured to control the source, gate and/orVcom voltages). Shared components may include display electrodes,substrates, connectors and/or connections. As another example, thedisplay device 160 may be operated in part or in total by the processingsystem 110.

It should be understood that while many embodiments of the presenttechnology are described in the context of a fully functioningapparatus, the mechanisms of the present technology are capable of beingdistributed as a program product (e.g., software) in a variety of forms.For example, the mechanisms of the present technology may be implementedand distributed as a software program on information bearing media thatare readable by electronic processors (e.g., non-transitorycomputer-readable and/or recordable/writable information bearing mediareadable by the processing system 110). Additionally, the embodiments ofthe present technology apply equally regardless of the particular typeof medium used to carry out the distribution. Examples ofnon-transitory, electronically readable media include various discs,memory sticks, memory cards, memory modules, and the like.Electronically readable media may be based on flash, optical, magnetic,holographic, or any other storage technology.

FIG. 2A shows a portion of an exemplary pattern of sensing elements 124configured to sense in the sensing region 170 associated with thepattern, according to some embodiments. For clarity of illustration anddescription, FIG. 2A shows the sensor electrodes 120 of the sensingelements 124 in a pattern of simple rectangles with the grid electrode122 disposed therebetween, and does not show various other components.The exemplary pattern of sensing elements 124 comprises an array ofsensor electrodes 120 _(X,Y) (referred collectively as sensor electrodes120) arranged in X columns and Y rows, wherein X and Y are positiveintegers, although one of X and Y may be zero. It is contemplated thatthe pattern of sensing elements 124 may comprises a plurality of sensorelectrodes 120 having other configurations, such as polar arrays,repeating patters, non-repeating patterns, a single row or column, orother suitable arrangement. Further, in various embodiments the numberof sensor electrodes may vary from row to row and/or column to column.In one embodiment, at least one row and/or column of sensor electrodes120 is offset from the others, such it extends further in at least onedirection than the others. The sensor electrodes 120 and grid electrodes122 are coupled to the processing system 110 and utilized to determinethe presence (or lack thereof) of an input object 140 in the sensingregion 170.

In a first mode of operation, the arrangement of sensor electrodes 120(120-1, 120-2, 120-3, . . . 120-n) may be utilized to detect thepresence of an input object via absolute sensing techniques. That is,processing system 110 is configured to modulate sensor electrodes 120 toacquire measurements of changes in capacitive coupling between themodulated sensor electrodes 120 and an input object to determine theposition of the input object. Processing system 110 is furtherconfigured to determine changes of absolute capacitance based on ameasurement of resulting signals received with sensor electrodes 120which are modulated.

The sensor electrodes 120 are typically ohmically isolated from eachother, and also ohmically isolated from the grid electrode 122. That is,one or more insulators separate the sensor electrodes 120 (and gridelectrode 122) and prevent them from electrically shorting to eachother. In some embodiments, the sensor electrodes 120 and grid electrode122 are separated by insulative gap 202. The insulative gap 202separating the sensor electrodes 120 and grid electrode 122 may befilled with an electrically insulating material, or may be an air gap.In some embodiments, the sensor electrodes 120 and the grid electrode122 are vertically separated by one or more layers of insulativematerial. In some other embodiments, the sensor electrodes 120 and thegrid electrode 122 are separated by one or more substrates; for example,they may be disposed on opposite sides of the same substrate, or ondifferent substrates. In yet other embodiments, the grid electrode 122may be composed of multiple layers on the same substrate, or ondifferent substrates. In one embodiment, a first grid electrode may beformed on a first substrate or first side of a substrate and a secondgrid electrode may be formed on a second substrate or a second side of asubstrate. For example, a first grid comprises one or more commonelectrodes disposed on a TFT layer of the display device 160 and asecond grid electrode is disposed on the color filter glass of thedisplay device 160. In one embodiment, the dimensions of the first gridelectrode are equal to the dimensions of the second grid electrode. Inone embodiment, at least one dimension of the first grid electrodediffers from a dimension of the second grid electrode. For example, thefirst grid electrode may be configured such that is disposed between afirst and second sensor electrode 120 and the second grid electrode maybe configured such that it overlaps at least one of the first and secondsensor electrodes 120 and the first grid electrode. Further, the firstgrid electrode may be configured such that it is disposed between afirst and second sensor electrode 120 and the second grid electrode maybe configured such that it only overlaps the first grid electrode and issmaller than the first grid electrode.

In a second mode of operation, the sensor electrodes 120 (120-1, 120-2,120-3, . . . 120-n) may be utilized to detect the presence of an inputobject via transcapacitive sensing techniques when a transmitter signalis driven onto the grid electrode 122. That is, processing system 110 isconfigured drive the grid electrode 122 with a transmitter signal andreceive resulting signals with each sensor electrode 120, where aresulting signal comprising effects corresponding to the transmittersignal, which is utilized by the processing system 110 or otherprocessor to determine the position of the input object.

In a third mode of operation, the sensor electrodes 120 may be splitinto groups of transmitter and receiver electrodes utilized to detectthe presence of an input object via transcapacitive sensing techniques.That is, processing system 110 may drive a first group of sensorelectrodes 120 with a transmitter signal and receive resulting signalswith the second group of sensor electrodes 120, where a resulting signalcomprising effects corresponding to the transmitter signal. Theresulting signal is utilized by the processing system 110 or otherprocessor to determine the position of the input object.

The input device 100 may be configured to operate in any one of themodes described above. The input device 100 may also be configured tooperate switch between any two or more of the modes described above.

The areas of localized capacitive sensing of capacitive couplings may betermed “capacitive pixels.” Capacitive pixels may be formed between anindividual sensor electrode 120 and reference voltage in the first modeof operation, between the sensor electrodes 120 and grid electrode 122in the second mode of operation, and between groups of sensor electrodes120 used as transmitter and receiver electrodes. The capacitive couplingchanges with the proximity and motion of input objects 140 in thesensing region 170 associated with the sensing elements 124, and thusmay be used as an indicator of the presence of the input object in thesensing region of the input device 100.

In some embodiments, the sensor electrodes 120 are “scanned” todetermine these capacitive couplings. That is, in one embodiment, one ormore of the sensor electrodes 120 are driven to transmit a transmittersignals. Transmitters may be operated such that one transmitterelectrode transmits at one time, or multiple transmitter electrodestransmit at the same time. Where multiple transmitter electrodestransmit simultaneously, the multiple transmitter electrodes maytransmit the same transmitter signal and effectively produce aneffectively larger transmitter electrode. Alternatively, the multipletransmitter electrodes may transmit different transmitter signals. Forexample, multiple transmitter electrodes may transmit differenttransmitter signals according to one or more coding schemes that enabletheir combined effects on the resulting signals of receiver electrodesto be independently determined. In one embodiment, multiple transmitterelectrodes may simultaneously transmit the same transmitter signal whilethe receiver electrodes are received with using a scanning scheme.

The sensor electrodes 120 configured as receiver sensor electrodes maybe operated singly or multiply to acquire resulting signals. Theresulting signals may be used to determine measurements of thecapacitive couplings at the capacitive pixels. Processing system 110 maybe configured to receive with the sensor electrodes 120 in a scanningfashion and/or a multiplexed fashion to reduce the number ofsimultaneous measurements to be made as well as the size of thesupporting electrical structures. In one embodiment, one or more sensorelectrodes are coupled to a receiver of processing system 110 via aswitching element such as a multiplexer or the like. In such anembodiment, the switching element may be internal to processing system110 or external to processing system 110. In one or more embodiments,the switching elements may be further configured to couple a sensorelectrode with a transmitter or other signal and/or voltage potential.In one embodiment, the switching element may be configured to couplemore than one receiver electrode to a common receiver at the same time.

In other embodiments, “scanning” sensor electrodes 120 to determinethese capacitive coupling comprises modulating one or more of the sensorelectrodes and measuring an absolute capacitance of the one or sensorelectrodes. In another embodiment, the sensor electrodes may be operatedsuch that more than one sensor electrode is driven and received with ata time. In such embodiments, an absolute capacitive measurement may beobtained from each of the one or more sensor electrodes 120simultaneously. In one embodiment each of the sensor electrodes 120 aresimultaneously driven and received with, obtaining an absolutecapacitive measurement simultaneously from each of the sensor electrodes120. In various embodiments, processing system 110 may configured toselectively modulate a portion of sensor electrodes 120. For example,the sensor electrodes may be selected based on, but not limited to, anapplication running on the host processor, a status of the input device,and an operating mode of the sensing device. In various embodiments,processing system 110 may be configured to selectively shield at leastportion of sensor electrodes 120 and to selectively shield or transmitwith the grid electrode(s) 122 while selectively receiving and/ortransmitting with other sensor electrodes 120.

A set of measurements from the capacitive pixels form a “capacitiveimage” (also “capacitive frame”) representative of the capacitivecouplings at the pixels. Multiple capacitive images may be acquired overmultiple time periods, and differences between them used to deriveinformation about input in the sensing region. For example, successivecapacitive images acquired over successive periods of time can be usedto track the motion(s) of one or more input objects entering, exiting,and within the sensing region.

In any of the above embodiments, multiple sensor electrodes 120 may beganged together such that the sensor electrodes 120 are simultaneouslymodulated or simultaneously received with. As compared to the methodsdescribed above, ganging together multiple sensor electrodes may producea course capacitive image that may not be usable to discern precisepositional information. However, a course capacitive image may be usedto sense presence of an input object. In one embodiment, the coursecapacitive image may be used to move processing system 110 or the inputdevice 100 out of a doze or low power mode. In one embodiment, thecourse capacitive image may be used to move a capacitive sensorintegrated circuit out of a doze mode or low power mode. In anotherembodiment, the course capacitive image may be used to move a hostintegrated circuit out of a doze mode or low power mode. The coursecapacitive image may correspond to the entire sensor area or only to aportion of the sensor area.

The background capacitance of the input device 100 is the capacitiveimage associated with no input object in the sensing region 170. Thebackground capacitance changes with the environment and operatingconditions, and may be estimated in various ways. For example, someembodiments take “baseline images” when no input object is determined tobe in the sensing region 170, and use those baseline images as estimatesof their background capacitances. The background capacitance or thebaseline capacitance may be present due to stray capacitive couplingbetween two sensor electrodes, where one sensor electrode is driven witha modulated signal and the other is held stationary relative to systemground or from stray capacitive coupling between a receiver electrodeand nearby modulated electrodes. In many embodiments, the background orbaseline capacitance may be relatively stationary over the time periodof a user input gesture.

Capacitive images can be adjusted for the background capacitance of theinput device 100 for more efficient processing. Some embodimentsaccomplish this by “baselining” measurements of the capacitive couplingsat the capacitive pixels to produce a “baselined capacitive image.” Thatis, some embodiments compare the measurements forming a capacitanceimage with appropriate “baseline values” of a “baseline image”associated with those pixels, and determine changes from that baselineimage.

In some touch screen embodiments, one or more of the sensor electrodes120 comprise one or more display electrodes used in updating the displayof the display screen. The display electrodes may comprise one or moreelements of the Active Matrix display such as one or more segments of asegmented Vcom electrode (common electrode(s)), a source drive line,gate line, an anode sub-pixel electrode or cathode pixel electrode, orany other display element. These display electrodes may be disposed onan appropriate display screen substrate. For example, the commonelectrodes may be disposed on the a transparent substrate (a glasssubstrate, TFT glass, or any other transparent material) in some displayscreens (e.g., In Plane Switching (IPS), Fringe Field Switching (FFS) orPlane to Line Switching (PLS) Organic Light Emitting Diode (OLED)), onthe bottom of the color filter glass of some display screens (e.g.,Patterned Vertical Alignment (PVA) or Multi-domain Vertical Alignment(MVA)), over an emissive layer (OLED), etc. In such embodiments, thedisplay electrode can also be referred to as a “combination electrode”,since it performs multiple functions. In various embodiments, each ofthe sensor electrodes 120 comprises one or more common electrodes. Inother embodiments, at least two sensor electrodes 120 may share at leastone common electrode. While the following description may describe thatsensor electrodes 120 and/or grid electrode 122 comprise one or morecommon electrodes, various other display electrodes as describe abovemay also be used in conjunction with the common electrode or as analternative to the common electrodes. In various embodiments, the sensorelectrodes 120 and grid electrode 122 comprise the entire commonelectrode layer (Vcom electrode).

In various touch screen embodiments, the “capacitive frame rate” (therate at which successive capacitive images are acquired) may be the sameor be different from that of the “display frame rate” (the rate at whichthe display image is updated, including refreshing the screen toredisplay the same image). In various embodiments, the capacitive framerate is an integer multiple of the display frame rate. In otherembodiments, the capacitive frame rate is a fractional multiple of thedisplay frame rate. In yet further embodiments, the capacitive framerate may be any fraction or integer of the display frame rate. In one ormore embodiments, the display frame rate may change (e.g., to reducepower or to provide additional image data such as a 3D displayinformation) while touch frame rate maintains constant. In otherembodiment, the display frame rate may remain constant while the touchframe rate is increased or decreased.

Continuing to refer to FIG. 2A, the processing system 110 coupled to thesensor electrodes 120 includes a sensor module 204 and optionally, adisplay driver module 208. The sensor module 204 includes circuitry 205configured to drive at least one of the sensor electrodes 120 forcapacitive sensing during periods in which input sensing is desired. Inone embodiment, the sensor module is configured to drive a modulatedsignal onto the at least one sensor electrode to detect changes inabsolute capacitance between the at least one sensor electrode and aninput object. In another embodiment, the sensor module is configured todrive a transmitter signal onto the at least one sensor electrode todetect changes in a transcapacitance between the at least one sensorelectrode and another sensor electrode. The modulated and transmittersignals are generally varying voltage signals comprising a plurality ofvoltage transitions over a period of time allocated for input sensing.In various embodiments, the sensor electrodes 120 and/or grid electrode122 may be driven differently in different modes of operation. In oneembodiment, the sensor electrodes 120 and/or grid electrode 122 may bedriven with signals (modulated signals, transmitter signals and/orshield signals) that may differ in any one of phase, amplitude and/orshape. In various embodiments, three modulated signal and transmittersignal are similar in at least one shape, frequency, amplitude and/orphase. In other embodiments, the modulated signal and the transmittersignals are different in frequency, shape, phase, amplitude and phase.The sensor module 204 may be selectively coupled one or more of thesensor electrodes 120 and/or the grid electrode 122. For example, thesensor module 204 may be coupled selected portions of the sensorelectrodes 120 and operate in either an absolute or transcapacitivesensing mode. In another example, the sensor module 204 may be adifferent portion of the sensor electrodes 120 and operate in either anabsolute or transcapacitive sensing mode. In yet another example, thesensor module 204 may be coupled to all the sensor electrodes 120 andoperate in either an absolute or transcapacitive sensing mode. Thesensor module 204 is also configured to operate the grid electrode 122as a shield electrode. Processing system 110 is configured to operatethe grid electrode 122 as a shield electrode that may shield sensorelectrodes 120 from the electrical effects of nearby conductors. In oneembodiment, processing system is configured to operate the gridelectrode 122 as a shield electrode that may shield sensor electrodes120 from the electrical effects of nearby conductors and guard thesensor electrodes 120 from grid electrode 122, at least partiallyreducing the parasitic capacitance between the grid electrode 122 andthe sensor electrodes 120. In one embodiment, a shielding signal isdriven onto the grid electrode 122. The shielding signal may be a groundsignal, such as the system ground or other ground, or any other constantvoltage (i.e., non-modulated) signal. In another embodiment, operatingthe grid electrode 122 as a shield electrode may comprise electricallyfloating the grid electrode. In embodiment, gird electrode 122 is ableto operate as an effective shield electrode while being electrodefloated due to its large coupling to the other sensor electrodes. Inother embodiment, the shielding signal may be referred to as a guardingsignal where the guarding signal is a varying voltage signal having atleast one of a similar phase, frequency and amplitude as the modulatedsignal driven on to the sensor electrodes. In one or more embodiment,routing (e.g., traces 240 and/or 242) may be shielded from responding toan input object due to routing beneath the grid electrode 122 and/orsensor electrodes 120, and therefore may not be part of the activesensor electrodes, shown as sensor electrodes 120.

In one or more embodiments, capacitive sensing (or input sensing) anddisplay updating may occur during at least partially overlappingperiods. For example, as a common electrode is driven for displayupdating, the common electrode may also be driven for capacitivesensing. In another embodiment, capacitive sensing and display updatingmay occur during non-overlapping periods, also referred to asnon-display update periods. In various embodiments, the non-displayupdate periods may occur between display line update periods for twodisplay lines of a display frame and may be at least as long in time asthe display update period. In such embodiment, the non-display updateperiod may be referred to as a long horizontal blanking period, longh-blanking period or a distributed blanking period, where the blankingperiod occurs between two display updating periods and is at least aslong as a display update period. In one embodiment, the non-displayupdate period occurs between display line update periods of a frame andis long enough to allow for multiple transitions of the transmittersignal to be driven onto the sensor electrodes 120. In otherembodiments, the non-display update period may comprise horizontalblanking periods and vertical blanking periods. Processing system 110may be configured to drive sensor electrodes 120 for capacitive sensingduring any one or more of or any combination of the differentnon-display update times. Synchronization signals may be shared betweensensor module 204 and display module 208 to provide accurate control ofoverlapping display updating and capacitive sensing periods withrepeatably coherent frequencies and phases. In one embodiment, thesesynchronization signals may be configured to allow the relatively stablevoltages at the beginning and end of the input sensing period tocoincide with display update periods with relatively stable voltages(e.g. near the end of a input integrator reset time and near the end ofa display charge share time). A modulation frequency of a modulated ortransmitter signal may be at a harmonic of the display line update rate,where the phase is determined to provide a nearly constant chargecoupling from the display elements to the receiver electrode, allowingthis coupling to be part of the baseline image.

The sensor module 204 includes circuitry 205 configured to receiveresulting signals with the sensing elements 124 comprising effectscorresponding to the modulated signals or the transmitter signals duringperiods in which input sensing is desired. The sensor module 204 maydetermine a position of the input object 140 in the sensing region 170or may provide a signal including information indicative of theresulting signal to another module or processor, for example,determination module 206 or a processor of the electronic system 150(i.e., a host processor), for determining the position of the inputobject 140 in the sensing region 170.

The display driver module 208 may be included in or separate from theprocessing system 110. The display driver module 208 includes circuitry207 confirmed to provide display image update information to the displayof the display device 160 during non-sensing (e.g., display updating)periods. In one embodiment, the sensor module 204, and display drivermodule 208 may be comprised within a common integrated circuit (firstcontroller). In another embodiment, two of the sensor module 204, sensormodule 204 and display driver module 208 are comprised in a firstintegrated circuit and the other one of the three modules is comprisedin a second integrated circuit. In those embodiments comprising multipleintegrated circuits, a synchronization mechanism may be coupled betweenthem, configured to synchronize display updating periods, sensingperiods, transmitter signals, display update signals and the like.

As discussed above, the sensor electrodes 120 of the sensing elements124 may be formed as discrete geometric forms, polygons, bars, pads,lines or other shape, which are ohmically isolated from one another. Invarious embodiments, ohmically isolated comprises passively isolated,where active switches may be configured to couple different sensorelectrodes to the same signal during a period of time. The sensorelectrodes 120 may be electrically coupled through circuitry to formelectrodes of having larger plan area relative to a discrete one of thesensor electrodes 120. The sensor electrodes 120 may be fabricated fromopaque or non-opaque conductive materials, or the combination of thetwo. In embodiments wherein the sensor electrodes 120 are utilized witha display device, it may be desirable to utilize non-opaque conductivematerials for the sensor electrodes 120. In embodiments wherein thesensor electrodes 120 are not utilized with a display device, it may bedesirable to utilize opaque conductive materials having lowerresistivity for the sensor electrodes 120 to improve sensor performance.Materials suitable for fabricating the sensor electrodes 120 includeITO, aluminum, silver, copper, molybdenum and conductive carbonmaterials, among others and various sensor electrodes may be formed of adeposited stack of different conductive materials. The sensor electrodes120 may be formed as contiguous body of conductive material havinglittle or no open area (i.e., having a planar surface uninterrupted byholes), or may alternatively be fabricated to form a body of materialhaving openings formed therethrough. For example, the sensor electrodes120 may be formed from a mesh of conductive material, such as aplurality of interconnected thin metal wires. In one embodiment, atleast one of the length and width of the sensor electrodes 120 may be ina range of about 1 to about 2 mm. In other embodiments, at least one ofthe length and width of the sensor electrodes may be less than about 1mm or greater than about 2 mm. In other embodiment, the length and widthmay not similar, and one of the length and width may be in the range ofabout 1 to about 2 mm. Further, in various embodiments, the sensorelectrodes 120 may comprise a center to center pitch in the range ofabout 4 to about 5 mm; however, in other embodiments, the pitch may beless than about 4 mm or greater than about 5 mm.

The grid electrode 122 may be fabricated similar to the sensorelectrodes 120. The sensor electrodes 120 and the grid electrode 122 maybe coupled to the processing system 110 utilizing conductive traces 240,242 (shown in phantom). The conductive traces 240, 242 may be formed inthe same plane at least one of the sensor electrodes 120 and the gridelectrode 122, or may be formed on one or more separate substrates andconnected to the respective electrodes 120, 122 by vias (not shown).Conductive traces 240 and 242 may be formed on a metal layer disposedsuch that the sensor electrodes 120 are between the metal layer and theinput object. In one embodiment the metal layer comprises source driverlines and/or gate lines for a display device. The conductive traces 240,242, and vias between them may be obscured from a user by a black masklayer disposed between them and the user of the display device. At leastone of the conductive traces 240 and 242 may comprise one or morerouting traces (conductors) in the source driver metal layer. In one ormore embodiments such a layer may be referred to as metal interconnectlayer two. Further, conductive traces 240 and/or 242 may be disposed ona metal layer between source driver lines. Alternately, at least one ofthe conductive traces 240 and 242 may comprise one or more conductors inthe gate driver metal layer or gate driver lines not configured fordisplay updating. Further, conductive traces 240 and/or 242 may bedisposed on a metal layer between gate driver lines. In anotherembodiment, at least one of the conductive traces 240 and 242 maycomprise one or more conductors in the Vcom jumper metal layer or Vcomlines not otherwise configured for display updating. Further, conductivetraces 240 and/or 242 may be disposed on a metal layer between gateelectrodes. In other embodiments the metal layer is included in additionto a layer comprising the source driver lines and/or gate lines. Aportion of the conductive traces 140, 142 may also be formed laterallyoutward of the areal bounds of the sensing elements 124. In variousembodiments, the conductive traces 240 and/or 242 may be disposed in aVcom electrode jumper layer. The Vcom electrode jumper layer may bereferred to as metal layer three or a metal interconnect layer three. Inone embodiment, conductive traces may be disposed on both a source drivelayer and a Vcom electrode jumper layer. In various embodiments, thedisplay device may comprise a “dual gate” or half source driver”configuration, allowing conductive routing traces 240 and/or 242 to bedisposed between source drivers on the source driver layer. In one ormore embodiments, orthogonal directions of connections between theconductive traces 240 and 242 they may be place on separate layers withvias between them

The grid electrode 122 is disposed between at least two of the sensorelectrodes 120. The grid electrode 122 may at least partiallycircumscribe the plurality of sensor electrodes 120 as a group, and mayalso, or in the alternative, completely or partially circumscribe one ormore of the sensor electrodes 120. In one embodiment, the grid electrode122 is a planar body 212 having a plurality of apertures 210, eachaperture 210 circumscribing a respective one of the sensor electrodes120. Accordingly, the grid electrode 122 separates and circumscribes atleast 3 or more of sensor electrodes 120, and in this example, separatesand circumscribes all of sensor electrodes 120. The gap 202 spaces thebody 212 from the sensor electrode 120 disposed in the aperture 210. Inone or more embodiments, the field electrode 122 is configured tosubstantially fill the space defined by the gap 202. In one embodiment asecond grid electrode may be disposed on a substrate between gridelectrode 122 and a touch input layer. The second grid electrode may bethe same size as grid electrode 122, or larger than grid electrode 122such that is overlaps one more sensor electrodes 120 and grid electrodeor smaller than grid electrode 122 such that it overlaps a portion ofthe grid electrode 122. In various embodiments, the grid electrode 122is disposed between at least two of sensor electrodes 120 such that thegrid electrode 122 is on different layer (i.e., different substrate orside of the same substrate) and overlaps a portion of at least twosensor electrodes and the gap between the sensor electrodes. In theembodiments where the sensor electrodes 120 comprise one or more commonelectrodes, the sensor electrodes may comprise the entirety of thecommon electrode layer.

The grid electrode 122 may also be segmented. The segmentation of thegrid electrode 122 may allow segments of the grid electrode 122 be lessvisible. The segments may be interconnect using traces or vias, so thatthe all the segments of the grid electrode 122 may be drivensimultaneously with a common signal. Alternatively, one or more of thesegments of the grid electrode 122 may be driven independently tofacilitate scanning of the sensor electrodes 120 when configured asreceiver electrodes in certain modes of operation as discussed furtherbelow.

As shown in the enlargement of FIG. 2A, the grid electrode 122 mayinclude a first segment 230, a second segment 232 and a third segment234. The first and second segments 230, 232 are offset from each otherand sandwich a column of sensor electrodes, shown as sensor electrodes120 _(2,1), 102 _(2,2). Although not shown in the enlargement, the firstsegment 230 also separates the column of sensor electrodes 120 _(2,Y)from sensor electrode 102 _(1,Y) while the second segment 232 separatesthe column of sensor electrodes 120 _(2,Y) from sensor electrode 102_(3,Y). The third segment 234 is disposed between neighboring sensorselectrodes 120 within a column, shown as sensor electrodes 120 _(2,1),102 _(2,2). Two or more of the segments 230, 232, 234 may beindependently driven, for example as transmitter electrodes.

FIG. 2B illustrates an alternative array of sensor elements 124 that maybe used in the input device 100 of FIG. 1. As illustrated in FIG. 2B,sensor elements 124 include a grid electrode 122 that may comprisesubstantially more surface area than the sensor electrodes 120. In theembodiment of FIG. 2B the grid electrode 122 at least partiallycircumscribes one or more sensor electrodes 120, for example asindicated by reference arrow 290. Additionally, or in the alternative,the grid electrode 122 completely circumscribes at least one sensorelectrode 120 and only partially circumscribes other sensor electrodes120, for example as indicated by reference arrows 290 and 292. In otherembodiments, the grid electrode 122 may completely circumscribe all ofthe sensor electrodes 120. Although not shown in FIG. 2B, it iscontemplated that the grid electrode 122 may be segmented as describedwith reference to FIG. 2A.

FIG. 2C illustrates an alternative array of sensor elements 124 that maybe used in the input device 100 of FIG. 1. As illustrated in FIG. 2C,sensor elements 124 includes more than one grid electrode, collectivelyreferred to as grid electrode 122 and illustratively shown as gridelectrodes 122 _((A,B)), where A and B are non-zero integers. In theembodiment of FIG. 2C, each grid electrode 122 at least partiallycircumscribes a different set of sensor electrodes 120, wherein a set ofsensor electrodes is defined as a group of sensor electrodes that are atleast partially circumscribed by a common one of the grid electrodes122. Each grid electrode 122 may be substantially similar in and sizeand circumscribe the same number of sensor electrodes 120; however, inother embodiments, the grid electrodes 122 may differ in at least one ofsize and the number sensor electrodes 120 at least partiallycircumscribed. Further, while the embodiment of FIG. 2C illustrateseight rid electrodes 122, in other embodiments, the input device 100 maycomprise two or more grid electrodes 122. In one embodiment, each gridelectrode 122 may be independently coupled to processing system 110 viadifferent conductive routing traces, shown as traces 242 _((1,1)), 242_((1,B)), 242 _((A,1)), and 242 _((A,B)). In other embodiment, two ormore grid electrode 122 may be coupled to processing system 110 via acommon conductive routing trace 242, in other words, the traces 242_((1,1)), 242 _((1,B)), 242 _((A,1)), and 242 _((A,B)) are gangedtogether. In such an embodiment, a multiplexer (or similar circuitry)may be used to switch between grid electrodes 122.

The plurality of grid electrodes 122 may be arranged in an orientationhaving an aerial extent extending farther in a first direction than asecond direction, the second direction orthogonal to the firstdirection. In one embodiment, each gird electrode 122 is arranged in anorientation having an aerial extent extending farther in the firstdirection than the second direction. In another embodiment, each girdelectrode 122 is arranged in an orientation having an aerial extentextending farther in the second direction than the first direction. Inyet other embodiments, each grid electrode 122 is arranged in anorientation having an aerial extent extending a substantially equaldistance in the first and second directions. Further, the gridelectrodes 122 may be configured such that one or more grid electrode122 has an aerial extent which is oriented differently than at least oneother grid electrode 122. For example, a first grid electrode 122 mayextend further in the first direction than the second direction and asecond grid electrode 122 may extend further in the second directionthan the first. In other examples, other combinations of grid electrode122 orientations are possible. In other embodiments, the grid electrodes122 may be oriented such that each grid electrode 122 is substantiallysimilar in size. At least one of the sensor electrodes 120 or sets ofsensor electrodes 120 may be similarly configured as described abovewith reference to the grid electrodes 122.

In some embodiments, a set of sensor electrodes 120 circumscribed by asingle grid electrode 122 may be aligned in a single row. In otherembodiments, a set of sensor electrodes 120 circumscribed by a singlegrid electrode 122 may be linearly aligned in a single row, such asshown in the embodiment depicted in FIG. 2C. In yet other embodiments, aset of sensor electrodes 120 circumscribed by a single grid electrode122 may be aligned in a plurality of rows, such as shown in theembodiment depicted in FIG. 2D. The number and/or orientation of thesensor electrodes 120 circumscribed by one grid electrode 122 may be thesame as, or different than, the number and/or orientation of the sensorelectrodes 120 circumscribed by a different grid electrode 122.

In the embodiments, one or more sensor electrodes 120 may share acoupling to the processing system 110. The sensor electrodes 120 may begrouped such that at least two are coupled in a direction that isorthogonal to the orientation of the grid electrode 122. For example,multiple sensor electrodes 120 _((3,1)), 120 _((3,2)), 120 _((3,Y-1)),and 120 _((3,Y)) have an orientation that is orthogonal to gridelectrode 122 _((1,1)) and may be coupled to a common conductive routingtrace 240 ₃. In another example, each sensor electrode 120 may becoupled to a different conductive routing trace 240 and to a common pinof processing system 110. A multiplexer (or similar circuit element) maybe coupled to the conductive routing trace or traces 240 so that thesensor electrodes 120 may be individually coupled to the processingsystem 110 when sharing a conductive routing trace 240. In one otherexample, each sensor electrode 120 may be coupled to a differentconductive routing trace 240, where each conductive routing trace 240 iscoupled to a different pin of processing system 110. Processing system110 may be configured to simultaneously receive with multiple sensorelectrodes 120 or receive with each sensor electrode 120 independently.In one embodiment, processing system 110 may be configured to receivewith a plurality of sensor electrodes 120 using a scanning, timemultiplexed, scheme when more than one grid electrode is driven with atransmitter signal. The grid electrodes may be adjacent to each other ornon-adjacent to each other. In one embodiment, two sensor electrodes maybe simultaneously received with while grid electrode that corresponds toone of the sensor electrodes is driven with a transmitter signal.

Processing system 110 may be configured to simultaneously drivetransmitter signals onto each grid electrode 122 and receive resultingsignals with the sensor electrodes 120. In such an embodiment, each gridelectrode 122 may be driven with a transmitter signal that is based on adifferent one of a plurality of digital codes. The digital codes may beany code such that they provide mathematical independent results. In oneembodiment, the digital codes for the set of transmitters aresubstantially orthogonal—i.e., exhibit very low cross-correlation, as isknown in the art. Note that two codes may be considered substantiallyorthogonal even when those codes do not exhibit strict, zerocross-correlation. In a particular embodiment, for example, the digitalcodes are pseudo-random sequence codes. In other embodiments, Walshcodes, Gold codes, or another appropriate quasi-orthogonal or orthogonalcodes are used. In another embodiment, processing system 110 isconfigured to simultaneously drive the grid electrodes 122 with the sametransmitter signal while independently receiving with the sensorelectrodes 120. Some substantially orthogonal codes may be selected thathave near zero sums which reduce the effect of the codes coupling todisplay elements, one set of such codes are circulant codes where eachcode vector is a rotation of the other vectors.

Processing system 110 may be configured to scan through the gridelectrodes 122, driving transmitter signals on to the grid electrodes122 one at a time, while receiving with the sensor electrodes 120. Inone embodiment, only those sensor electrodes 120 that are circumscribedby the grid electrode 122 which is being driven are received with. Inother embodiments, all of or some portion of the sensor electrodes 120may be received with a grid electrode 122 that is being driven.

Processing system 110 may be configured to selectively configure thegrid electrode 122 or sensor electrodes 120 based on the positionalinformation of an input object 140. For example, in one embodiment,processing system 110 may drive transmitter signals onto the gridelectrodes 122 such that the grid electrode is driven as one large gridelectrode 122. Processing system 110 may selectively drive only aportion of the grid electrodes 122 that are proximate the detected inputobject or objects 140. In another embodiment, For example, in oneembodiment, processing system 110 may drive shielding signals onto thegrid electrodes 122 such that the grid electrode is driven as one largegrid electrode 122. Further, processing system 110 may selectively driveonly a portion of the grid electrodes 122 with a shielding signal thatare proximate the detected input object or objects 140. In oneembodiment the driving scheme (as discussed above) used to drive thegrid electrode 122 may vary based on the positional information of theinput object or objects 140.

FIG. 3 through FIG. 5 depict embodiments of the sensing elements 124operating in a first mode configured for absolute sensing. Operating thegrid electrode 122 as a shield electrode allows for the reduction of thesize of the sensor electrodes 120 and/or to control the capacitivecoupling between the sensor electrodes 120 and input objects.

Referring first to FIG. 3, a simplified sectional view of the sensingelements 124 of FIG. 1 is shown. The grid electrodes 122 are illustratedcoplanar with the sensor electrodes 120. The grid electrode 122 maycomprise the common electrodes and overlap the pixel electrodes, similarto the sensor electrodes 120. In at least some embodiments, the gridelectrode 122 may be at least as big, if not larger than the sensorelectrodes 120. The grid electrode 122 and the sensor electrodes 120 mayoptionally be fabricated from a single layer of conductive material. Inone embodiment, each sensor electrode 120 has a dimension correspondingto a dimension of pixel elements of the display device 160 such that thesensor electrodes 120 do not substantially block a portion of adisplayed image. In other embodiments, each sensor electrode 120 has adimension corresponding to a non-integer number of pixel elements. Insuch an embodiment, the division between sensor electrode and betweensensor electrodes and grid electrode 122 may occur within a pixelelement. The distance between the grid electrode 122 and sensorelectrode 120 may be equal to the distance between sub-pixels. In oneembodiment, the spacing between adjacent the sensor electrodes 120,i.e., the distance across the gap 202, is less than or equal to thespacing of a black-mask of the display device 160, for example, in therange of a few micro-meters. In one embodiment, the spacing betweenadjacent the sensor electrodes 120, i.e., the distance across the gap202, is equal to one or more subpixels of the display device 160.

Optionally as seen in the enlargement depicted at the upper left portionof FIG. 2A, the sensor electrode 120 may be paired with a floatingelectrode 250. In one embodiment, the sensor electrodes 120, floatingelectrode(s) 250 and the grid electrode 122 may cover the entire Vcomplane. The shape of the paired sensor electrode 120 and the floatingelectrode 250 may be selected for specific applications, and in oneembodiment, the area of the paired sensor electrode 120 is smaller thanthe area of the floating electrode 250, for example by less than 50percent.

The grid electrode 122, as discussed above, is disposed between thesensor electrodes 120. In another embodiment, the grid electrode 122comprises one or more common electrodes of the display device. In suchembodiments, the grid electrode 122 is laterally spaced apart from thetwo sensor electrodes 120 a distance corresponding to the distancebetween pixel elements of the display device. The width of the portionof the grid electrode 122 disposed between adjacent sensor electrodes120 may be balanced to improve the settling time of the grid electrode,as well as number of conductive traces 142 and their connections todifferent portions of the grid electrode 122, if segmented. In oneembodiment, the grid electrode 122 is disposed such that it is betweenand at least partially overlaps with at least two sensor electrodes.

In the first mode of operation, the sensor electrodes 120 are configuredto both be driven with a modulated signal provided by the processingsystem 110 and the capacitive coupling between the modulated sensorelectrode(s) and an input object is measured. In one or more embodimentsresulting signals comprises effect corresponding to the modulatedsignals are received with the sensor electrodes and the capacitivecoupling between the sensor electrode(s) and the input object is basedon the resulting signals. The measurements may be utilized by theprocessing system 110 or other processor to determine the position ofthe input object based on a measurement of absolute capacitance. As amodulated signal is driven onto the sensor electrodes 120 by theprocessing system 110, an electric field is generated by each sensorelectrode 120 and extends from the plane of the sensor electrodes 120.

The shielding signal provided by the processing system 110 to the gridelectrode 122. The shielding signal may be a varying voltage (i.e.,guarding signal) or a constant (i.e., fixed potential) voltage such assystem ground or any other constant voltage. In one embodiment, theshielding signal and the relative position of the grid electrode 122between adjacent sensor electrodes 120 functions to reduce thecapacitive coupling between sensor electrodes and the grid electrode122. Since the grid electrode 122 may be configured to reduce theparasitic capacitive coupling between sensor electrodes 120 and gridelectrode 122, greater positional accuracy of an input object 140 may bedetermined. Additionally, as the grid electrode 122 shields and guardssensor electrodes 120, the input device 100 is also able to provideaccurate multi-touch finger tracking capability without blurring theobject across multiple sensor electrodes 120 since the dimensions of thesensor electrodes 120 may be reduced. Thus, in many embodiments, use ofthe grid electrode 122 enable of good multi-touch performance even whileonly a portion of the common electrode layer of the input device 100 isoperating in an absolute sensing mode.

In various embodiments, a property of the shielding signal may bevaried. For example, in a first time period, the grid electrode 122 maybe driven with a shielding signal that is in-phase with the modulatedsignal and having a first amplitude selected. In a second time period,the amplitude of the shielding signal can be reduced to a secondamplitude which is less than the first amplitude or the amplitude of theshielding signal may be increases to a third amplitude which is greaterthan the first amplitude. In a third time period, the amplitude ofshielding signal could be further reduced to a substantially fixedpotential. Furthermore, the grid electrode may be alternatively bedriven with a shielding signal that is out of phase with the modulatedsignal provided to the sensor electrodes 120. In one embodiment, theamplitude and/or phase of the shielding signal may be varied as inputobjects progressively approach the input device 100. In one embodiment,the amplitude and/or phase of the shielding signal may be varied basedon the operation mode of the input device 100. For example, the gridelectrode 122 may be driven with a first shielding signal when thesensor electrodes 120 are driven as transmitter electrodes and a secondshielding signal when the sensor electrodes 120 are driven as absolutesensor electrodes. The first and second sensor electrodes may differ inat least one of a phase, amplitude and/or frequency. In one embodiment,the grid electrode 122 may be electrically floated when the sensorelectrodes 120 are driven as transmitter electrodes and a shieldingsignal when the sensor electrodes 120 are driven as absolute sensorelectrodes.

In conventional input devices not configured with grid electrodes, theseparation between sensor electrodes results in a capacitive couplingbetween individual sensor electrodes and/or between the sensor electrodeand other conductors such as display electrodes. In various embodiments,in input devices not configured with grid electrodes, as the distanceswhich the sensor electrodes are separated decreases and/or the distancebetween which the sensor electrodes and other conductors are separateddecreases, the capacitive coupling between the sensor electrodesincreases. The capacitive coupling is present spatially across multipleindividual sensor electrodes. This results in degraded multi-touchperformance, as responses of individual touching fingers are lessspatially localized.

However, the grid electrode 122 being configured to shield, activelydriven with a shielding signal or electrically floated, while sensingtouch decreases cross-coupling (capacitive coupling) of sensorelectrodes 120 and neighboring conductors. Thus, the grid electrode 122functions to prevent the effects of nearby conductors on the sensorelectrodes 120.

FIG. 4 is a simplified sectional view of another embodiment of thesensor assembly. The grid electrode 122 is located on a layer between aninput surface and the sensor electrodes 120. The grid electrode 122 isillustrated parallel with a plane defined by the sensor electrodes 120.The grid electrode 122 and the sensor electrodes 120 may be fabricatedon the same substrate, or on different substrates comprising the inputdevice 100 and/or display device 160. The sensor electrodes 120 and gridelectrode 122 are generally aligned with the pixel elements of thedisplay device 160 as described above. Optionally, one or more of thegrid electrode 122 may overlap with the sensor electrodes 120.

The grid electrode 122 is spaced above the sensor electrodes 120 by adistance 400. The spacing of the grid electrode 122 above the sensorelectrodes 120 may control the capacitive coupling between input objectsand the sensor electrodes 120 as compared to the coplanar grid electrode122 illustrated in FIG. 3 thereby providing increased positionalaccuracy of an input object 140. While the grid electrode 122 isillustrated as being above the sensor electrodes 120, in otherembodiments, the grid electrode may be disposed below the sensorelectrodes 120. In one embodiment a second grid electrode may bedisposed between and on the same layer as the sensor electrode below thegrid electrode 122. In one embodiment the grid electrode 122 may overlaptwo sensor electrodes of the plurality of sensor electrodes 120. In oneor more embodiment, the grid electrode 122 may overlap at least aportion of sensor electrodes 122. The grid electrode 122 may comprise abody of material having openings formed therethrough. For example, thegrid electrode 122 may be formed from a mesh of conductive material,such as a plurality of interconnected thin metal wires. One or more ofthe interconnected thin metal lines may overlap a sensor electrode.Further, the interconnected thin metal wires may be disposed on anylayer above the sensor electrodes 120 and may be disposed using aseparate process. Further, multiple thin metal lines of the conductivematerial may overlap each sensor electrode.

In the embodiment, shown in FIG. 5, having some of the sensor electrodes120, specifically sensor electrodes 502, directly beneath the gridelectrode 122 allows the sensor electrodes 120 to be smaller compared tothe sensor electrodes 120 illustrated in FIG. 4. The smaller sensorelectrodes 120 illustrated in FIG. 5 have capacitance to an input objectdifferent than the larger sensor electrodes.

Any of the arrangement of sensing elements 124 illustrated in FIGS. 2-5may be alternatively utilized in the second mode of operation. Asdiscussed above, in the second mode of operation the sensor electrode120 are utilized to detect the presence of an input object viatranscapacitive sensing when a transmitter signal is driven onto thegrid electrode 122. That is, the grid electrode 122 is configured totransmit a transmitter signal provided by the processing system 110 andeach sensor electrode 120 is configured to receive a resulting signalcomprising effects corresponding to the transmitter signal, which isutilized by the processing system 110 or other processor to determinethe position of the input object. The settling performance intranscapacitive second mode is improved over that of a conventionalbars/stripes sensors in that the large surface area of the gridelectrode 122 may have a reduced resistance as compared to conventionaltransmitter electrodes in that the transmitter signal does not have tobe driven through long traces routed down the sides of the displayactive area as in conventional transmitter electrodes. The settlingperformance of the grid electrode 122 can be further improved in amatrix-addressed scheme by reducing the effective capacitance of thegrid electrode 122 by applying a shielding signal configured to guardthe grid electrode 122 from those sensor electrodes 120 which areactively being utilized as receiver electrodes.

In one embodiment, the grid electrode 122 operating in the second modefunctions as a single transmitter electrode and each of the arrayedmatrix of sensor electrodes 120 functions as a receiver electrode fortranscapacitance sensing operation. With all the sensor electrodes 120functioning as receiver electrodes, all resulting signals may beacquired at one moment in time. Alternatively, multiplexing can beutilized to scan through sensor electrodes 120 functioning as receiverelectrodes.

In one embodiment of operation in the second mode, the sensor electrodes120 may be addressed in a matrix by utilizing a grid electrode 122 thathas been divided into multiple segments (such as segments 230, 232, 234illustrated in FIG. 2A) that can be independently and sequentiallydriven to determine the X and Y location of the input object 140relative to the input device 100. Thus, the sensor electrodes 120 actingas receiver electrodes may be scanned while using different portions ofthe grid electrode 122 as transmitter electrodes to increase thepositional accuracy of the input device 100. For example, one or moregeometric characteristics of the grid electrode 122, such as theorientation (aspect ratio), geometric profile and/or plan area, may be,in the second mode of operation, changed using switches or any othermeans to selectively connect segments of the grid electrode 122.Changing the geometric characteristics of the grid electrode 122 may beuseful when, in one mode, use of the grid electrode 122 is desirable inone configuration, yet in another mode, when transcapacitive sensingbetween sensor electrodes 120, configuration of at least some or all ofthe area of the grid electrode 122 as part of either the transmitter orreceiver electrodes.

As discussed above, it may be advantageous to selectively operate ineither the first or second modes. For example, a single structure ofsensing elements 124 can operate in an absolute sensing mode (i.e.,first mode) utilizing the grid electrode 122 to control the capacitivecoupling between the sensor electrodes 120 and an input object, orselectively in the second mode utilizing the grid electrode 122 as atransmitter electrode and the matrix of sensor electrodes 120 asreceivers electrodes, thereby increasing definition between multipleobjects in the sensing regions 170 and providing improved detection ofmotion objects within the sensing regions 170. In one embodiment, theabsolute sensing mode may be a tunable, selectively switching betweendifferent amplitudes and/or phases. Selectively operating in differentmodes may be based on a whether an input object is determined to be infirst portion of the sensing region or a second portion of the sensingregion, the first portion being between the second portion and an inputsurface of the sensing device. The phase and/or amplitude of the signaldriven onto the grid electrode 122 and/or the sensor electrodes 120 maybe varied based on the operating mode.

As discussed above, the sensing elements 124 may be configured tooperation in other transcapacitive modes. For example, FIG. 6 is asimplified schematic plan view of sensing elements 124 configured foroperating in a transcapacitive third mode of operation.

In a third mode of operation, the sensor electrodes 120 are split into agroup of transmitter electrodes 602 and a group of receiver electrodes604. The particular sensor elements 120 designated as transmitterelectrodes 602 and receiver electrodes 604 may be assigned by theprocessing system 110 according to a predefined criteria or predefinedsequence. For example, the particular sensor elements 120 designated astransmitter electrodes 602 and receiver electrodes 604 may be selectedin response to an input object in a predefined location in the sensingregion 170 or a predefined resulting signal received on one or more ofthe receiver electrodes 604. Alternatively, the sensor elements 120designated as transmitter electrodes 602 and receiver electrodes 604 maybe assigned in accordance to a predetermined programmed sequence.

In the embodiment depicted in FIG. 6, each transmitter electrodes 602 islocated adjacent to at least one receiver electrode 604. Two or moretransmitter electrodes 602 may also bound a single receiver electrode604. During sensing in the third mode of operation, the grid electrode122 may be floated or driven with a shielding signal that has a constantvoltage. The shielding signal may be driven out of phase with thetransmitter signal, modulated similar to the transmitter signal, havethe same or different waveform or amplitude of the transmitter signal orcombinations of thereabove.

Optionally, during the third mode of operation one or more of the sensorelectrodes 120 functioning as the transmitter electrodes 602 may beswitched to function as a receiver electrode 604. The switching ofsensor electrodes 120 between receivers and transmitters may beaccomplished by multiplexing. As shown in the embodiment depicted inFIG. 7, all the sensor electrodes 120 functioning as transmitterelectrodes 602 in FIG. 6 have been switch to function as receiverelectrodes 704, while all the sensor electrodes 120 functioning asreceiver electrodes 604 in FIG. 6 have been switched to function astransmitter electrodes 702. The switching between assignment as receiverand transmitter electrodes may occur over two or more multiplexingsteps. Switching of the sensor electrodes 120 between functioning asreceiver and transmitter electrodes allows a capacitive image to becaptured in reduced period of time compared to scanning through each ofthe transmitter electrodes individually. For example, the modulatepattern shown in FIGS. 6 and 7 allows a capacitive image to be capturedafter two modulate periods. In other embodiments, various other sensingpatterns may be used, where more or less modulate periods may be used.For example, the sensor electrodes may be selectively configured astransmitter and receiver electrodes such that 4 or 8 modulate periodsare needed to determine the capacitive image. However, in otherembodiments, other modulate patterns may be used that need any number ofmodulate periods to determine the capacitive image.

FIG. 8 is a flow diagram of one embodiment of a method 800 for detectingpresence of an input object. The method 800 utilizes a capacitivesensing device, such as the input device 100 described above, to performan absolute sensing routine. The capacitive sensing device utilized toperform the method 800 includes a grid electrode disposed between afirst sensor electrode and a second sensor electrode of a plurality ofsensor electrodes. The method begins at step 802 by driving a modulatedsignal onto a first sensor electrode of the sensor electrodes 120 whilein a first mode of operation. The method 800 proceeds to step 804 bydetermining the absolute capacitive coupling of the first sensorelectrode of the sensor electrodes 120, while in the first mode ofoperation. The resulting signal may be utilized to determine thepresence, or lack thereof, of an input object in the sensing region 170by the processing system 110 or the electronic system 150.

Non-limiting examples of the first mode of operation have been providedabove with reference to FIG. 2A through FIG. 5. It is contemplated thatthe method 800 may be practiced utilizing other sensor configurationsassociated with one or more grid electrodes.

The method 800 may include driving a shielding signal on the firstshaping electrode to reduce the parasitic capacitive coupling and/orinterference from nearby conductors in resulting signals fromneighboring sensor electrodes in simultaneously with the performance ofstep 802. The method 800 may also include changing the shielding signaldriven on the first shaping electrode over subsequent iterations ofsteps 802 and step 804. Non-limiting examples of the methodology forchanging the shielding signal are described above at least withreference to FIGS. 2, 3 and 4.

The method 800 may optionally include step 806 in which the mode ofoperation is switched to a transcapacitive mode of operation. Forexample, the absolute sensing mode provided by steps 802 and 804 may beswitched to a transcapacitive mode of operation, such as to one or bothof a second mode of operation, illustrated by the flow diagram of FIG.9, and to a third mode of operation, illustrated by the flow diagram ofFIG. 10.

The method 800 additionally includes optional a step in which the drivermodule 208 drives a display update signal onto the common electrodeswhich comprise one or more of the sensor electrodes 120. The displayupdate signal is generally provide during a non-display update (i.e.,sensing) period, for example, during the period when step 802 and step804 are not being performed.

Portions of the method 800 may optionally be repeated over one or moreiterations, as indicated by arrows 810, 812, 814. The method 800 mayalso terminate without performance of one of step 806. The method 800may also be performed on other input devices, including those notassociated with display devices.

FIG. 9 is a flow diagram of another embodiment of a method 900 fordetecting presence of an input object. FIG. 9 is a flow diagram of oneembodiment of a method 900 for detecting presence of an input objectutilizing the second mode of operation, i.e., a transcapacitive sensingroutine. The method 900 utilizes a capacitive sensing device, such asthe input device 100 described above, the capacitive sensing devicehaving a grid electrode disposed between a first sensor electrode and asecond sensor electrode of a plurality of sensor electrodes. The methodbegins at step 902 by driving a transmitter signal onto a grid electrode122 while in a second mode of operation. The method 900 proceeds to step904 by receiving a resulting signal with the sensor electrodes 120comprising effects corresponding to the transmitter signal, while in thefirst mode of operation. The resulting signal may be utilized todetermine the presence, or lack thereof, of an input object in thesensing region 170 by the processing system 110 or the electronic system150.

Non-limiting examples of the second mode of operation have been providedabove with reference to FIG. 2A. It is contemplated that the method 900may be practiced utilizing other sensor configurations associated withone or more grid electrodes.

The method 900 may also include changing the signal driven on the gridelectrode 122 over subsequent iterations of step 902 and step 904. Forexample, the grid electrode 122 may be driven with a first transmittersignal having a first amplitude to detect input objects in closeproximity to the input device, then driven with a shielding signalhaving a second amplitude to detect input objects further from and infar field proximity to the input device with less interference fromneighboring electrodes.

The method 900 may also include multiplexing the transmitter signaldriven on different segments of the grid electrode 122 over subsequentiterations of step 902 and step 904. For example, one segment of thegrid electrode 122 may be driven with a transmitter signal to detectinput objects in one portion of the sensing region 170 the input device100, then another segment of the grid electrode 122 may be driven with atransmitter signal to detect input objects in a different portion of thesensing region 170 the input device 100, thereby improving theresolution of the determination of the location of the input objectrelative to the input device 100.

The method 900 may optionally include step 906 in which the mode ofoperation is switched to either a third (transcapacitive) mode ofoperation, illustrated by the flow diagram of FIG. 10, or to a first(absolute) mode of operation, as previously described with reference tothe flow diagram of FIG. 8.

The method 900 additionally includes optional step in which the drivermodule 208 drives a display update signal onto the common electrodeswhich comprise one or more of the sensor electrodes 120. The displayupdate signal is generally provide during a display update (i.e.,sensing) period, for example, during the period when step 902 and step904 are not being performed.

The method 900 may also terminate without performance of step 906. Themethod 900 may also be performed on other input devices, including thosenot associated with display devices.

Portions of the method 900 may optionally be repeated over one or moreiterations, as indicated by arrows 910, 912, 914. The method 900 mayalso terminate without performance of step 906. The method 900 may alsobe performed on other input devices, including those not associated withdisplay devices.

FIG. 10 is a flow diagram of one embodiment of a method 1000 fordetecting presence of an input object utilizing the second mode ofoperation, i.e., a transcapacitive sensing routine. The method 1000utilizes a capacitive sensing device, such as the input device 100described above, the capacitive sensing device having a grid electrodedisposed between a first sensor electrode and a second sensor electrodeof a plurality of sensor electrodes. The method begins at step 1002 bydriving a transmitter signal onto a first group of sensor electrodes 120(also shown as transmitter electrode 602 in FIG. 6) while in a thirdmode of operation. The method 1000 proceeds to step 1004 by receiving aresulting signal with a second group of sensor electrodes 120 (alsoshown as receiver electrode 604 in FIG. 6) comprising effectscorresponding to the transmitter signal, while in the first mode ofoperation. The resulting signal may be utilized to determine thepresence, or lack thereof, of an input object in the sensing region 170by the processing system 110 or the electronic system 150.

Non-limiting examples of the third mode of operation have been providedabove with reference to FIG. 6, with optional steps described withreference to FIG. 7. It is contemplated that the method 1000 may bepracticed utilizing other sensor configurations associated with one ormore grid electrodes.

The method 1000 may also include multiplexing the transmitter signaldriven on different groups of the sensor electrodes 120 over subsequentiterations of step 1002 and step 1004. For example as shown by thesequence of assignment of the sensor electrodes 120 as transmitterelectrodes and receiver electrodes, a first group of the transmitterelectrodes 602 may be driven with a transmitter signal and a secondgroup of the receiver electrodes 604 may be configured as receiverelectrodes to detect resulting signals corresponding to the transmittersignal, then first group of the transmitter electrodes 602 arereconfigured as receiver electrodes (shown as 704 in FIG. 7) and thesecond group of the receiver electrodes 604 are reconfigured astransmitter electrodes (shown as 702 in FIG. 7).

The method 1000 may optionally include step 1006 in which the mode ofoperation is switched to either a second (transcapacitive) mode ofoperation, illustrated by the flow diagram of FIG. 9, or to a first(absolute) mode of operation, as previously described with reference tothe flow diagram of FIG. 8.

The method 1000 additionally includes optional step in which the drivermodule 208 drives a display update signal onto the common electrodeswhich comprise one or more of the sensor electrodes 120. The displayupdate signal is generally provide during a non-display update (i.e.,sensing) period, for example, during the period when step 1002 and step1004 are not being performed.

The method 1000 may also terminate without performance of step 1006. Themethod 1000 may also be performed on other input devices, includingthose not associated with display devices.

Portions of the method 1000 may optionally be repeated over one or moreiterations, as indicated by arrows 1010, 1012, 1014. The method 1000 mayalso terminate without performance of step 1006. The method 1000 mayalso be performed on other input devices, including those not associatedwith display devices.

FIG. 11 is an exploded side view of one embodiment of an exemplarydisplay device 160 having an integrated input device 160 illustratingalternative locations for a grid electrode 122. The grid electrode 122of the input device 100 may be within or external to the display device160. The exploded view of the display device 160 allows variousalternative positions of the grid electrode 122 to be illustrated withinthe display device 160. The sensor electrodes 120 associated with thegrid electrode 122 are not shown in the illustration of FIG. 11.

The display device 160 generally includes a plurality of transparentsubstrates positioned over a substrate 1124 (i.e., TFT glass) of thedisplay device 160. In one embodiment, a plurality of transparentsubstrates positioned over the substrate 1124 of the display device 160includes a lens 1112, an optional polarizer 1114, an optionalanti-shatter film 1116, and a color filter glass (CFG) 1118. In oneembodiment, the grid electrode 122 is disposed at least partially on oneof these transparent substrates, and/or on the substrate 1124 of thedisplay device 160. In the embodiment depicted in FIG. 11, the gridelectrode 122 is shown disposed on a lower surface (i.e. surface facingsubstrate 1124 of the active element of the lens 1112.

The grid electrode 122 may be disposed on (1) a separate transparentsubstrate, (2) at least partially on or fully formed one of thesubstrates 1112, 1114, 1116, 1118, or (3) at least partially on, fullyformed on, or within the substrate 1124 of the active element of thedisplay device.

Additionally shown in FIG. 11 are alternative positions (shown inphantom) for locating the grid electrode 122. For example, the gridelectrode 122 may be positioned on, at least partially formed directlyon, or fully formed directly on an upper side of the optional polarizer1114, as illustrated by reference numeral 1132. The grid electrode 122may alternatively be positioned on, at least partially formed directlyon, or fully formed directly on a lower side of the optional polarizer1114, as illustrated by reference numeral 1134. The grid electrode 122may alternative be positioned on, at least partially formed directly on,or fully formed directly on an upper side of the optional anti-shatterfilm 1116, as illustrated by reference numeral 1136. The grid electrode122 may alternatively be positioned on, at least partially formeddirectly on, or fully formed directly on a lower side of the optionalanti-shatter film 1116, as illustrated by reference numeral 1138. Thegrid electrode 122 may alternative be positioned on, at least partiallyformed directly on, or fully formed directly on an upper side of the CFG1118, as illustrated by reference numeral 1140. The grid electrode 122may alternatively be positioned on, at least partially formed directlyon, or fully formed directly on a lower side of the CFG 1118, asillustrated by reference numeral 1142. In such embodiment, the gridelectrode may be aligned with the black mask disposed on the CFG 1118.In any of the above embodiment, the grid electrode 122 may be comprisedof a wire mesh material, where the wire mesh material patterned tocontrol the electric field lines of the driven sensor electrodes.

The grid electrode 122 may alternative be positioned on, at leastpartially formed directly on, or fully formed directly on an upper sideof the substrate 1124 of the active element, as illustrated by referencenumeral 1144. Where the grid electrode 122 is formed as least partiallyformed directly on, formed fully on, or within the substrate 1124 of thedisplay device; one or both of the grid electrode 122 and the sensorelectrodes 120 may be comprised of common electrodes (segments ofsegmented V-corn electrode 1120), such as illustrated in FIG. 2A, FIG.2B and FIG. 3.

In one embodiment, the dimensions of each of the sensor electrodes 120correspond to the dimension of pixel elements. For example, at least oneof the length and width of each sensor electrode 120 may correspond toan integer multiple of the number of sub-pixels. In other embodiment, atleast one dimension of a sensor electrode may correspond to a portion ofa pixel element. For example, one of the length and width may correspondto a non-integer multiple of a number of sub-pixels. In one embodiment,the dimensions of each sensor electrode 120, for example having aquadrilateral form, are at least about 30 sub-pixel elements by at leastabout 30 sub-pixel elements. In other embodiment, the dimensions of eachsensor electrode may correspond an M sub-pixel elements, by N sub-pixelelements; where M and N may be the same or different. Further M and Nmay each be less than about 30 sub-pixel elements or greater than about30 sub-pixel elements. In various embodiments, one or more dimensions ofthe sensor electrode correspond to a non-integer number of sub-pixelselements. For example, the length or width of a sensor electrode maycorrespond to a portion of a sensor electrode and the gap between sensorelectrodes and other sensor electrodes or between sensor electrodes andthe grid electrode may be within a sub-pixel.

In one embodiment, the space between each sensor electrode 120 and thegrid electrode 122 may correspond to the distance between sub-pixelselements. For example, the dimension of the isolation space between eachsensor electrode 120 and the grid electrode 122 may be equal to about 5micrometers; however, the dimension of the isolation space may begreater than or less than about 0.5 micrometers. Further, the center tocenter pitch of sensor electrodes 120 may be in a range of about 30 toabout 50 sub-pixels. However, the pitch may be less than about 30sub-pixels and greater than about 50 sub-pixels.

In yet other embodiments, each sensor electrode may have a length and/orwidth equal to about 1 millimeter. However, the sensor electrodes 120may have a length and/or width that is greater than 1 millimeter.Further, the center to center pitch of sensor electrodes 120 may be in arange of about 2 to about 5 millimeters. However, the pitch may be lessthan about 2 millimeters and greater than about 5 millimeters.

In one embodiment, the dimensions of the grid electrode 122 maycorrespond to the dimensions of the sub-pixel elements. For example, thewidth of the grid electrode 122 that is disposed sensor electrodes 120may correspond to an integer multiple of the number of sub-pixels.Further, the width of the grid electrode 122 that is disposed sensorelectrodes 120 may correspond to a non-integer multiple of the number ofsub-pixels. In one embodiment, the dimensions of the width of the gridelectrode 122 is in the range of least about 10 sub-pixel elements to atleast about 120 sub-pixel elements. In other embodiments, the width ofthe grid electrode 122 may be less than 10 sub-pixel elements or greaterthan 120 sub-pixel elements. Further, the grid electrode may beconfigured to have a width in the range of about 0.5 millimeters toabout 120 millimeters; however, widths below 0.5 millimeters and above120 millimeters are also possible. In other embodiments, the gridelectrode 122 may be configured to have various widths.

Each of the sensor electrodes 120 may be the same size and shape,however, in various embodiments; at least one sensor electrode may havea different size and or shape than the other sensor electrodes 120. Thesize and shape of the sensor electrode 120 may correspond to a locationof the sensor electrodes. For example, a sensor electrode 120 locatednear the edge of the sensing region may be sized and/or shapeddifferently than a sensor electrode 120 located near the center of thesensing region.

FIGS. 12A-12E illustrate various differently shaped sensor electrodes120 and grid electrode 122. In the embodiment of FIG. 12A, sensorelectrodes 1201A and 1201B are illustrated as having a different sizethan the other sensor electrodes. Further, as illustrated in FIG. 12A,the position of the sensor electrodes having a different size may vary.In one embodiment, sensor electrode 1201A and sensor electrode 1201B maybe aligned in a common row and/or column of the plurality of sensorelectrodes. FIG. 12B illustrates an embodiment of sensor electrodes 120,where each sensor electrode is a polygon having less than four sides.Further, as illustrated, in one embodiment, alternating sensorelectrodes may be rotated versions of each other (e.g., sensorelectrodes 1202A and sensor electrode 1202 b). The sensor electrodes mayalso be mirror symmetric about an axis. For example, sensor electrodes1202A and 1202C are mirror symmetric about axis 1204. In the embodimentof FIG. 12C, the sensor electrodes 120 comprise a polygon shape havingmore than four sides; however, in other embodiment, any number of sidesmay be possible. Further the grid electrode 122 of the embodiment ofFIG. 12B and FIG. 12C comprises a plurality of non-parallel and parallelsegments. In the embodiment of FIG. 12, the sensor electrodes 120 may beinterleaved with each other, such that at least one sensor electrode hasa protrusion that is interleaved with another sensor electrode. In oneembodiment, alternating sensor electrodes may have protrusions andcutouts such that the sensor electrodes may be interleaved. In otherembodiments the sensor electrodes may be interleaved with more than twoneighboring sensor electrodes. As illustrated by FIG. 12E, in oneembodiment a first set of sensor electrodes are at least partiallydisposed between a second set of sensor electrodes. For example, sensorelectrodes 1208A and 1208B are disposed such that they are interleavedbetween sensor electrodes 1208C and 1208D. In other embodiments, thesensor electrodes comprise one or more protrusions, but the sensorelectrodes are not interleaved with each other. Further, grid electrode122 may have a reduced width in one more areas between sensor electrodes(e.g., segment 1206). In further embodiments, additional shapes notlisted above are also contemplated. In various embodiments, the sensorelectrodes may have more than one protrusion at various differentangles. For example, shapes such as, but not limited to a “star”,“asterisk”, “circular”, “diamond”, and “ellipses” are also contemplated.In one or more embodiments, the shape of the sensor electrodes may beselected to improve the fringing field lines between sensor electrodesand other sensor electrodes or sensor electrodes and the input object.The sensor electrodes may have one or more protrusions (perpendicular toeach other or at any angle with each other), one or more angled sides,one or more curved sides, or any combination of the above.

Thus, the embodiments and examples set forth herein were presented inorder to best explain the embodiments in accordance with the presenttechnology and its particular application and to thereby enable thoseskilled in the art to make and use the invention. However, those skilledin the art will recognize that the foregoing description and exampleshave been presented for the purposes of illustration and example only.The description as set forth is not intended to be exhaustive or tolimit the invention to the precise form disclosed. In view of theforegoing, the scope of the present disclosure is determined by theclaims that follow.

What is claimed is:
 1. A processing system for an input device, theprocessing system comprising: a sensor module, comprising sensorcircuitry configured to couple to a plurality of sensor electrodes, thesensor module is configured to drive a first sensor electrode of theplurality of sensor electrodes to acquire first changes of absolutecapacitance during a first non-display update period of a display frameand a second sensor electrode of the plurality of sensor electrodes toacquire second changes of absolute capacitance during a secondnon-display update period of the display frame, wherein the firstnon-display update period and the second non-display update period occurbetween different pairs of display line update periods of the displayframe and are at least as long as a display line update period of thedisplay frame.
 2. The processing system of claim 1, wherein the sensormodule is further configured to drive a grid electrode with a shieldingsignal during the first and second non-display update periods, whereinat least a segment of the grid electrode is disposed between the firstand second sensor electrodes.
 3. The processing system of claim 2,wherein the sensor module is further configured to drive the gridelectrode with the shielding signal comprising a varying voltage.
 4. Theprocessing system of claim 1 further comprising: a determination moduleconfigured to determine a capacitive image based on the first and secondchanges of absolute capacitance, and wherein the first changes ofabsolute capacitance corresponds to a first pixel of the capacitiveimage and the second changes of absolute capacitance corresponds to asecond pixel of the capacitive image.
 5. The processing system of claim1, wherein the first changes of absolute capacitance corresponds to afirst pixel of a capacitive image and the second changes of absolutecapacitance corresponds to a second pixel of the capacitive image. 6.The processing system of claim 1, wherein the plurality of sensorelectrodes are disposed in a matrix array of discrete sensor electrodes.7. The processing system of claim 1, wherein each of the plurality ofsensor electrodes comprise a common electrode of a plurality of commonelectrodes of a display device.
 8. The processing system of claim 1further comprising: a display driver module coupled to a plurality ofdisplay electrodes of a display device, the display driver modulecomprising circuitry configured to drive the display electrodes toupdate a display of the display device.
 9. The processing system ofclaim 8, wherein the sensor module is disposed on a first integratedcircuit and the display driver module is disposed on a second integratedcircuit.
 10. The processing system of claim 8, where the sensor moduleand the display driver module are disposed on a first integratedcontroller.
 11. An input device comprising: a plurality of sensorelectrodes, each sensor electrode of the plurality of sensor electrodescomprising at least one common electrode of a plurality of commonelectrodes of a display device, the plurality of sensor electrodesdisposed in a matrix array of discrete sensor electrodes; a processingsystem coupled to the plurality of sensor electrodes and configured to:drive a first sensor electrode of the plurality of sensor electrodes forcapacitive sensing during a first non-display update period of a displayframe, and drive a second sensor electrode of the plurality of sensorelectrodes for capacitive sensing during a second non-display updateperiod of the display frame, wherein the display frame comprises aplurality of display line update periods and wherein the firstnon-display update period and the second non-display update period occurbetween different pairs of the plurality of display line update periodsand wherein the first non-display update period and the secondnon-display update period are at least as long as one of the displayline update periods.
 12. The input device of claim 11 furthercomprising: a grid electrode at least partially disposed between thefirst sensor electrode and the second sensor electrode, wherein the gridelectrode comprises at least one common electrode of the plurality ofcommon electrodes, and wherein the processing system is configured todrive the grid electrode with a shielding signal during the first andsecond non-display update periods.
 13. The input device of claim 12,wherein the processing system, when driving the first sensor electrodeand the second sensor electrode for capacitive sensing, is furtherconfigured to drive the first and second sensor electrodes with amodulated signal, and wherein the shielding signal and the modulatedsignal are similar in at least one of phase and amplitude.
 14. The inputdevice of claim 11, wherein, the processing system, when driving thefirst sensor electrode and the second sensor electrode for capacitivesensing, is further configured to drive the first and second sensorelectrodes with a modulated signal for absolute capacitive sensing. 15.The input device of claim 11 further comprising: a grid electrodewherein at least one segment of the grid electrode is disposed betweenthe first sensor electrode and the second sensor electrode.
 16. Theinput device of claim 15, wherein the processing system is configured todrive the grid electrode with a shielding signal during the first andsecond non-display update periods.
 17. A method for capacitive sensingwith a display device comprising an integrated capacitive sensingdevice, the method comprising: driving a first plurality of sensorelectrodes to acquire first changes of absolute capacitance during afirst non-display update period of a display frame and a secondplurality of sensor electrodes to acquire second changes of absolutecapacitance during a second non-display update period of the displayframe, wherein the first non-display update period occurs between firstand second display line update periods of the display frame and whereinthe second non-display update period occurs between third and fourthdisplay update periods of the display frame, wherein the first andsecond non-display update periods are at least as long as a display lineupdate period of the display frame; and determining a capacitive imagebased on the first and second changes of absolute capacitance.
 18. Themethod of claim 17 further comprising driving a gird electrode with ashielding signal during the first and second non-display update periods,wherein the grid electrode is at least partially disposed between thefirst and second sensor electrodes.
 19. The method of claim 17 furthercomprising driving the second plurality of sensor electrodes with ashielding signal during the first non-display update time period.